A review of data from clinical trials of weight-loss drugs has concluded that weight regain begins about eight weeks after stopping these medications, and continues up to 20 weeks, before stabilising at about 26 weeks.
The paper ‘Trajectory of the body weight after drug discontinuation in the treatment of anti-obesity medications’ published in BMC Medicine, an open access, transparent peer-reviewed general medical journal, also observed that at 52 weeks, the subjects of the trial still weighed less than they did before starting medication, but the weight loss was reduced compared to when they were actively taking the drugs.
11 clinical trials
The researchers Han Wu et al, from the Department of Endocrinology and Metabolism, Peking University People’s Hospital, China, analysed data from 11 clinical trials with 1,573 people taking anti-obesity medication. These medications included: GLP-1 receptor agonists (such as semaglutide, liraglutide), orlistat, naltrexone-bupropion, and phentermine-topiramate. Randomised controlled trials of anti-obesity medications conducted in the population for at least four weeks and followed up for four or more weeks after discontinuation were included.
The review sought to examine the post-trial period when the drugs stop, estimate what happens to the weight of these patients, how much weight is regained, how soon do they begin to regain weight and the impact of lifestyle factors on weight. The researchers observed that people who lost more weight during treatment were more likely to regain weight, even if they continued lifestyle interventions (including diet and exercise). Those who started with a lower body mass index (BMI), meaning they were less overweight, showed more weight regain after stopping than those with higher BMI. Interestingly, people taking GLP-1-related drugs experienced more weight regain after stopping than those on other drugs, they reported in the paper.
Different weight regain was observed in subjects with different characteristics, the researchers said, adding that studies with a longer follow-up duration are required to further investigate the potential factors associated with weight change after discontinuation of treatment.
Hope to many
“This is an interesting study with robust meta analyses, but similar results have been shown in many other trials too,” says Dr. Nanditha, consultant diabetologist, Dr. A. Ramachandran’s Diabetes Hospitals, Chennai. “Any intervention, either when you step down or discontinue, will result in weight gain, even if it is lifestyle modifications.”
However, it is important to see the usefulness of these drugs in the context of the obesity epidemic. Obesity, originally, was looked upon as a risk factor, but is now considered a disease by itself. “Earlier, we did not have many tools to treat it, now these drugs are providing hope to people who can lose weight without surgery. What is clear is that the regain will not take you back to the baseline weight, so while expensive, these drugs should be considered an investment, because the benefits go beyond weight loss,” she said.
It may be remembered that another study, published recently in the journal Obesity, showed that semaglutide and tirzepatide — injectable GLP-1 drugs for obesity — produce lower weight loss in a real-world setting, as compared to during the clinical trial, because patients discontinue treatment or use lower maintenance dosages.
